1. Field of the Invention
The present invention relates to a molded case circuit breaker, and particularly, to a terminal module assembly for a molded case circuit breaker in which a terminal part of the molded case circuit breaker is constructed as a module assembly to allow a fast replacement of a terminal module, so that a type of terminal (e.g., a standard type, a plug-in type or a box type) can be fast changed.
2. Background of the Invention
In general, a molded case circuit breaker is an electrical device for protecting circuit and electrical loads by automatically breaking the electrical circuit upon occurring a fault current, such as over-current, ground fault current or short-circuit current, on the electrical circuit.
A molded case circuit breaker generally comprises a terminal part which connects a power source or an electrical load of the circuit, a switching mechanism which switches the circuit by contacting a fixed contact with a movable contact or separate them from each other within the molded case circuit breaker, and a trip mechanism which senses a fault current to trip the switching mechanism to a circuit-broken position.
The terminal part, for example, comprises an outer protrusion of the fixed contact and a terminal. The types of the terminal may include a box type terminal which is mostly used when wires at the power source side circuit and the load side circuit have “ring-shaped” terminals or “U-shaped” terminals, a plug-in type terminal which is used when the molded case circuit breaker is connected to the circuit by inserting the terminal into a terminal insertion hole on a plug-in base, and a standard type terminal as a typical bar-shaped terminal which is commonly used when wires in the circuit have a circular section.
Manufacturers of molded case circuit breakers manufacture the related art terminals monolithically with the molded case circuit breaker, without separately providing only the terminals. Accordingly, when the type of terminal should be changed according to an installation environment of the molded case circuit breaker, a user should purchase the whole molded case circuit breaker having the same type of terminal that he wants to get, in order to replace only the terminal.
To solve the inconvenience, the applicant of this invention has proposed a module-type terminal structure such as “module-type terminal structure of molded case circuit breaker” (Korean Patent Laid Open No. 2006-0087344, open date: Aug. 2, 2006).
By adapting the module-type terminal structure of the molded case circuit breaker proposed by the applicant of this application, the user does not have to purchase the whole molded case circuit breaker in order to replace only the type of terminal he desires to get. However, in case of a typical 3-phases Alternating Current molded case circuit breaker, when assembling each of 6 terminal modules (i.e., 3 terminal modules respectively at the load side and the power source side) to the molded case circuit breaker using screws, it takes long time and it is inconvenient for both of manufacturer and user.
Furthermore, the terminal module itself is a merely small component about several tens millimeters. Accordingly, it is difficult to separately fabricate, package and sell the terminal module. Also, the user may be in trouble for assembling the small component to the molded case circuit breaker.
In addition, the molded case circuit breaker may be restricted only to molded case circuit breakers which have, for example, a rail-mounted connection structure such that the replaceable terminal module can be connected thereto.